Radio system



.Sept 26 w39.. N. J. PIERCE Er AL RADIO SYSTEM Filed June 25, 1957 3Sheets-Sheet 1 TTORNEV Sem 269 i939 N. J. PIERCE ET AL 373,858

RADIO SYSTEM -Fiiedqune 2s, 1937 s sheets-'sheet 2 .Moron mmm# srsrm 2/2ab all-l MONITORING SYSTEM IIHIHIII RE C 0MM/VG SYSTEM FIG. 2

. N. L PIERCE FA. PoL/f//vG/-loR/v /N VEN TORS:

www

A T TOR/VF' Y N. J. PIERCE El' AL RADIO SYSTEM :s sheets-sheet 3 FiledJune 23. 1937 N. J. PIERCE' A. POL/NGHORN /N VEN TORS ATTORNEY PatentedSept. 26, i939 UNEEE STES PATENT @FFME RADIO SYSTEM Norman Si'. Pierce,Middletown, and Frank A. Polkinghorn, Montclair, N. J., assignors toBell Telephone Laboratories, Incorporated, New York, N. Y., acorporation of New York Application June 23, 1937, Serial No. 149,824

11 Claims. (Cl. Z50-11) This invention relates to radio communicationtion will also cause the discharge of all of the systems and moreparticularly to systems employcapacitors. ing sharply directive antennaarrays of the steer- The use of the capacitors makes it possible to abletype. integrate the signal for any angle over a period An object of theinvention is to provide means of time determined by the time constant ofthe for automatically steering suoli antenna systems, charging circuitand thus to give considerable particularly in such a Way as to foliowany exibility of operation. Changes in the direction or angle of arrivalof a There is also provided means for obtaining radio Wave. records ofthe field intensities indicated by the l0 U. S. Patent 2,041,60 to I-I.T. Friis, May i9, monitoring receiver and of the operation of the 101936, discloses and claims a radio system employservice phase Shiftersso as to provide a basis ing an end-on array of directive antennas whichfor the optimum adjustment of the operation of have their outputsconnected through phase shiftthe system.

ers to a common signal circuit. rEhe phase shift- This invention can bemore readily understood vers combine the outputs of the antennas inphase by reference to the following detailed description for any desiredangle of reception, giving an overin connection with the drawings inwhich: all characteristic which is highly directive. Also, Fig.` l is ageneral schematic drawing of one there is provided a common control forthe phase embodiment of the invention in a radio receiver; Shifters, sothat the angle of maximum response Fig. 2 is a schematic drawing 0f thecircuit may be changed at Will. A single antenna array details of theautomatic control system of Fig. l; 2c

may be used for several separate steerable Figs. 3, 4, 5 and 6 areDSTSDGCV@ VieWS 0f Cel"- branches by the use of a corresponding numbertain of the appalallS UllitS ShOWl SChematCally of phase Shiftersconnected in parallel to the in Fig. 2, Fig. 3 being the mOIllOlDgCommutaantenna units. When the system is used forv tors, Fig. 4 themanual range setting switch. Fig.

receiving, one of these sets may be used as an 5 the motor controlcommutator, and Fig. 6 the 25 exploring or monitoring circuit fordetermining ISCOYdel; and

the angles at which Waves are arriving. Fg- 7 ShOWS daglmmtcally amOdiCatOn In one embodiment of the present invention, of the phaseshifter control to permit operation such a monitoring circuit iscontinuously cyccai- Where the receiver is mounted at an intermediate "0ly operated and through the use of an automati- Point in the antennaarray 5") cally operated interlock, caused to control one or Similarreference numerals are used for the more of the other sets of phaseShifters so as to Same elements in all 0f the gU-TSS- so automaticallysteer such other branches that Fg- 1 ShOWS a multiple unit Steerableantenna their directions of maximum response correspond 0f the typedeSCIbeCl and Claimed in U. Patent to the directions at which Waves ofusable ainpli- 2,041,600 t0 H. T. FlS Of May 19, 1935, employed 3 tudeare arriving. In order to get a control rewith a two branch diversityradio receiver and sponsive to the i'ield pattern as indicated by the'l1-Sing the llOmatC Steering SYStem 0f this i11- explorlng action or"the monitoring branch, there VGDOH AS ShOWIl, the antenna array COmDTSeSare provided a group of similar capacitors con'- three antenna unitslil, Il and l2. It is understood that in any practical system there will40 40 nected to corresponding segments of a commutator swept by a brushdriven synchronously with usually be many more u DltS, lQ1lt Only threeare the monitoring phase Shifters, This brush is con- Shwn for the Sake0f SlmpllClW- nected to a rectifier in the output of the monitorcr'gsseoagelga lfuhal (fvll'lllncelegrsgl ing receiver and Consequently wmSupply to each detail'.J The antenna unit such as I0 is connected 45capacitor a charge corresponding to the strength to the input of aSelective radio frequency ank of the received signal at the particularinstant. plier I3 which has its output Connected to the When the Chargeon any of the Capacitors reaches first detector I4 of a triple detectionradio rea predetermined value, it will set into operation @givingCircuiti/ Heterodyning oscillations are the interlocking mechanism so asto so adjust Supplied 130 this detector in parallel with the sim- 50 llephase ShlfSTS 0f SelVC Chap-Del that the ilar detectors connected to theother antenna Corresponding CleC'VB array Characteristic Will units froman oscillator I5. The resultant interhave a maximum response at theangle of recepmediate frequency oscillations are selectively am.- tioncorresponding to the position of the monitorplifying in an intermediatefrequency amplier ing phase Shifters at such instant. This opera- I6.The output of this amplifier is connected to 55 three adjustable phaseShifters 2|, 3| and 4I in parallel. These may be, for example, of thetype disclosed and claimed in U. S. Patent 2,004,613 to Meacham, June11, 1935.

The phase shifter 2|, together with the corresponding phase Shifters 22and 23 of the other antenna units, constitute a rst service branch.Similarly the phase Shifter 3| andI the corresponding phase Shifters 32and 33 constitute a Second service branch and phase shifter 4I with thecorresponding phase Shifters 42 and 43 constitute a monitoring orexploring branch.

AS described in detail in the Friis patent, referred to above, each setof phase Shifters Such as 2|, 22 and 23 constitutes a separatelySteerable branch of the system and when the phase shifters 2| and 22 areproperly aligned and connected by the proper gear ratios to a controlShaft 20, the direction of maximum response of such branch may besteered by rotating the shaft 20. Phase Shifters 3| and 32 are similarlygeared to a control shaft 35, and phase Shifters 4| and 42 to themonitoring control shaft 45. lThe phase Shifters 23, 33 and 43 may bedummies.

The output of the phase Shifters 2| is connected through a selectiveintermediate frequency amplifier I1 to the input of the No. I Servicebranch, second detector 5| in parallel with the Similarly amplifiedoutputs of the phase Shifters 22 and 23. Similarly, the output of thephase shifter 3| after being amplified in the intermediate frequencyamplifler i3 is connected to the input of the second detector 52 of theNo. 2 Service branch, in parallel with the amplified outputs of thephase Shifters 32 and 33. The outputs of the monitoring phase Shifters4|, 42 and 43 after amplification in intermediate frequency amplifiersIS are connected to the monitoring branch Second detector 53.

Beating oscillations are supplied to the Second deterctors 5|, 52 and 53from a common oscillator 50. |The resulting second intermediatefrequency waves are amplified in the corresponding second intermediatefrequency amplifiers 54, 55 and 55.

In the case of the service branches, the outputs of the secondintermediate frequency amplifiers 54 and 55 are supplied to the Signaldetectors 5 and 53, respectively and the signal outputs combined in acommon signal circuit 60. Since, as described in detail in the Friispatent referred to above, the Signal currents in the service branches Iand 2 may arrive at the receiver over different paths, they may arriveat different times, and in order to compensate for this discrepancy intime of arrival there is inserted in the No. 2 service branch, which isassumed to be receiving the wave traveling over the shorter path, avariable audio delay network 59 which is controlled either manually orautomatically to bring the outputs of the two service branches into timephase.

The shaft 40 of the monitoring phase Shifters is continuously driven bya motor 45. During each revolution of the shaft 40 the major lobe of thedirective characteristic of the monitoring branch will make a completesweep of the operative angles of the branch, thereby serving to explorethe usable field of the system. As a result, value of the output currentof the intermediate frequency amplifier 56 will at any instant be anindication of the field intensity at the particular angle of receptioncorresponding to the angular position of the control shaft 40.

By the use of a cathode ray oscillograph having a sweep circuitcontrolled by a potentiometer on the Shaft 40 and a deiiection operatedby the rectified output current of the amplifier 56 there may beobtained a visual indication of this field pattern, as described inPatent 2,041,600.

In the System of this invention the output current of the intermediatefrequency amplifier 56 iS used for causing an automatic adjustment ofthe phase Shifters of the service branches. For this purpose, the outputcurrent of the amplifier 56 is supplied to a monitoring circuit |00which cooperates with a motor control circuit 200 on the shaft 30 tocontrol the phase Shifters 3| and 32 and similarly to the monitoringcircuit 300 which cooperates with a motor control circuit 400 on theShaft 20 for controlling the phase Shifters 2| and 22. The outputcurrent of the amplifier 56 is also supplied to the recorder circuit 500for giving a permanent record of the field pattern and also of theoperation of the service branch phase Shifters.

Reference will now be made to Fig. 2 which Shows in schematic form thedetails of the monitoring circuit |00, the control circuit 200 and therecorder circuit 500. The monitoring circuit 300 and motor controlcircuit 400 are not shown in detail as they are identical with thecorresponding circuits |00 and 200.

For the purpose of the automatic control there is provided on the shaft40 a double commutator I I0 and a single commutator |20. ('Ihemechanical construction of one embodiment of these commutators is Shownin Fig. 3.) Contacting with the commutators ||0 are two irl-phasebrushes I| I and I I2. There are provided a Series of condensers I3I,|32, |33, etc., each of which has one terminal connected to acorresponding one of the interconnected segments of the doublecommutator |I0 and all have their other terminals connected to thecommon ground circuit.

The output of the intermediate frequency am plier 56 is connectedthrough a tuned transformer |34 to a rectifier circuit including a dioderectifier |35 and a load resistor |36. A variable tap |38, on thenegative side 0f the grounded point |31 of the load resistor |36, isconnected through a variable resistor |39 to the brush I I I. The outputof the rectifier |35 may be connected through lead |55 to a cathode rayoscillograph for giving a visual indication of the eld pattern, aspreviously described.

A three-electrode vacuum tube |40 is operated as a vacuum tube voltmeteror voltage-respon- The grid of this tube |40 is consive device. nectedto the brush I|2, the input circuit being completed through the resistor|4`| to the grounded cathode. The anode of the vacuum tube |40 isconnected through the primary winding of a polarized relay |42 to theplate current battery |43, the anode circuit being completed to thecathode at the grounded terminal of the battery.

There is provided in circuit association with the relay |42 a secondpolarized relay |54. A battery |44 normally Supplies biasing current tothe secondary winding of this relay to hold the armature away from thecontact |45 which is connected to the brush III. The battery |44' isalso connected through a resistor |46, primary winding of the relay |54,and condenser |41 to ground for a purpose which will be described laterin connection With the operation of the system.

The armature of the relay |42 is connected to the winding of a relay |49which is normally unoperated and has its normally open contact |50connected to the brush |2| associated with the commutator |20. The lead|5| from the armature of the relay |42 also connects to the recordingsystem 5U!) as Will be later described.

Each of the segments of the commutator |2| is connected to the Windingof a relay |22 of a group of similar relays (only one of which isshown). A connection |52 connects the normally Open contact of the relay|22 to the motor control circuit 200 and similar connections areprovided for the other relays of the group.

As the motor 35 drives the control shaft 4) the brush makes contactsuccessively with the segments of the commutator Il, supplying to eachof the condensers |3 l, etc. a charge corresponding to the amplitude ofthe output current of the amplifier 56 at the particular instant. Thecapacity of each of these condensers and the resistance of the circuitare preferably so chosen that it takes an appreciable time (severalrevolutions of the brush to charge any one of the condensers to themaximum value of the voltage supplied by the rectifier. The time of thisintegrating period may be readily controlled by varying the variableresistor |39. Under normal conditions such as the beginning of a cycleof operation, the tube |40 is drawing plate current to hold the relay|42 in the operated position. At the same time that each of thecondensers |3l, etc. is receiving a charge through the brush thecumulative charge on such condenser is supplied to the grid of the tubemi! through the brush ||2. When such a charge reaches a predeterminedvalue, it will reduce the plate current of the tube Id@ and cause themomentary release of relay |152.

The release of relay |42 closes a circuit from condenser |41 through thecontact and armature of relay M2 and resistor |28 to ground causing thedischarge of condenser la?. The discharge current of the condenser lillflows, in parallel to the resistor |48 through the winding of relay |49causing the momentary operation of that relay. (This current also iiowsthrough the winding of relay 515 as will be later described.)

The condenser IM will then be recharged from the battery |44, throughresistor U56 and the primary winding of relay |52. This charging currentwill cause the operation of the relay his, which will hold up during thecharging period of the condenser, during which time the brush will beconnected through the connection |53 and armature of the relay |54 toground, forming a discharge circuit for each of the condensers |3|, etc.as the brush successively contacts the corresponding segments of thearmature IIEi. The charging period of the condenser Id is made such thatthe relay M3 will remain operated for a period sucient to discharge allof the condensers |3I, etc. which must be for at least one revolution ofthe brush Hl and preferably longer.

The operation of relay |59 completes a. circuit from a common battery26| through armature and contact of relay |159, brush |2|, thecorresponding segment of commutator l2@ and the winding of correspondingrelay |22, causing the operation of such relay. This will cause theparticular relay |22 to lock up through the circuit completed throughits own armature to produce the operation of the motor control circuit2m) of the phase shifter shaft 30.

Referring to the motor control system 200 there is provided a reversiblealternating current motor 35 for driving the shaft 35. This motor isprovided with a running winding 35 and a starting winding 3l, thecircuit of the latter of which is completed through a centrifugal switch(not shown) which will open up the circuit when the motor comes up tospeed, in a manner well known in the art. in the drawings, the motor 35is shown directly connected to the shaft 30 for the purpose ofsimplicity, though in actual practice it will usually be connectedthrough reduction gearing.

There is also provided on the shaft 3i) a commutator mechanism 2li! (themechanical arrangement of one embodiment of which is shown in Fig. 5).This commutator mechanism provides means for causing the shaft 353 to bebrought to any one of a plurality of positions by the shorter angularmovement of the shaft. It comprises a plurality of contact segments 2||and two segmental brushes 2 i2 and 2 I3 of equal circumferential length,one or the other of which contacts all but two of the commutatorsegments 2H. The brushes 2|2 and 2l3 are connected through leads 222 and223, respectively to a circuit including relays 2ill, 25B and 26@ forcontrolling the operation of the motor 35 to bring about the properangular adjustment of the shaft S.

The operation of this motor control system will be described inconnection with its operation to move the shaft Sil to one particularposition. Assuming a relay |22 has been operated by the operation of themonitoring system as previously described to complete a circuit fromground through the winding and armature of such relay |22 and lead |52to the corresponding armature segment 2H, there will then be cornpleteda circuit from this segment 2li through brush 2|2, lead 222, contact andlower inner armature of relay 21MB, winding of relay 23@ and battery 20|to ground. This will hold the relay |22 operated and cause the operationof relay 231B.

The operation of relay 2353 causes the following operations: (i) theupper inner armature of the relay opens up the circuit 223 from thebrush 2 I3 to prevent false operation of the relay 22u; (2) closes acircuit from the left terminal of the alternating current source 28@through the upper outer armature of relay 23d, lead 28d, Winding ofrelay 2l@ to the right-hand terminal of the source 289, and (3) closes acircuit from the left-hand terminal of source 28! through lower armatureof relay 232, winding of relay 250 to the right-hand terminal of source28u.

The operation of relay 250 closes a circuit from the source 28B to thestarting winding 3l of the motor 35. Simultaneously, the operation ofthe relay 21!! (as above described) closes a circuit from the source 280to running winding 35' ci the motor. The direction of application of thealternating current to the winding 3l causes the motor to start in onedirection which will be termed forward as indicated by the arrowassociated with the armature ZIE).

The motor will then drive the shait 3@ until the insulated space betweenthe brushes 2 l2 and 2 I3 reaches the contact 2 at which instant theground connection for the lead 222 is broken causing the release ofrelay 23E] and consequently of the relays 255 and 27|) opening thealternating current circuits to the windings 35 and 3? and causing themotor 35 to stop.

In order to bring about the rapid stopping of the motor 35 so that thesegment between the brushes 2|2 and 2| 3 will not override the contact2li, there is associated with the contacts of the relay 210 a motorbrake circuit 299. This circuit comprises a battery 29| having avoltagey considerably higher than the normal voltage of the runningwinding 36. Connected in series with the battery 29| are a resistor 292and a condenser 293. The terminals of the condenser 293 are alsoconnected to the back contacts of the relay 219. During the period thatthe motor 35 is running, these contacts are open and the condenser 293charges to the full voltage of the battery 29|. When the relay 219releases to stop the motor 35 the condenser is connected to runningwinding 36 through the back contacts of the relay so that the Vcondenserdischarges through the running winding 36bringing the motor to an abruptstop. During the period in which the motor 35 is not in motion, theconnection from winding 36 to the battery 29| is maintained but theresistor 292 is made of such a value that the direct current through thewinding 36 will not be suiilcient to injure it.

If the operation of the monitoring system |09 causes the selection ofsuch a one of the other relays |22 that one of the contacts 2|| incontact with the brush 2| 3 is connected to ground, it Will cause theoperation of the relay 249 which Will set up a series of operationssimilar to that set up by the operation of relay 239 except that in thiscase the relay 265 instead of the relay 269 will be operated. It will benoted that the connection of the armatures of the relay 265 is such asto supply alternating current from the source 223 to the startingWinding 31 in the opposite direction to which it is supplied by theoperation of the relay 359. This will cause the motor 35 to rotate inthe reverse direction. In all other respects the operations are thesame.

As so far described, the monitoring system |00 operates throughout thefull range of variations of the phase Shifters mounted on the shaft 46.It is desirable in some cases to limit the operation to a portion onlyof the range, particularly When two or more service channels areoperated from the same antennae array as shown in Fig. 1. For thispurpose there is provided a manual range setting switch |63. Themechanical construction of such a switch is shown in Fig. 4 and themethod of connection in Fig. 2. This switch comprises two commutators|6| and |62 each having the. same number of segments or contacts as thecommutator bank i5. Contacting with each of the respective commutatorsis a semi-circular brush |65 and |64. Brush |63 is mounted on a gear i65and the brush |64 on a gear |66. The gears |65 and |66 are driven by therespective control knobs |61 and |68 through corresponding pinions. Eachof the gears |65 and |56 has cut therein a semi-circular aperture |69and |16 respectively. A scale |1| is mounted below the gears.

The corresponding segments of the commutators |6l and |62 are connectedin parallel and to the ungrounded terminals of the respective condensersof the group |34, |32, |33, etc. The brushes |63 and |64 are connectedto ground by the operation of the control knobs |61 and 65, thecorresponding brushes |63 and |64 can be made to short-circuit a desiredportion of the condensers |3i, |32, |33, etc. Those condensers which arenot short-circuited will represent that portion of the range of thesystem which will be operative. The portion of the scale |1| which isvisible through the apertures |69 and |10 Willindicate the operativerange for any particular setting.

Y In order to obtain a continuous record of the eld intensity pattern asindicated by the monitoring circuit, there is provided a recordingsystem 509 which operates in conjunction with the recording mechanism699, the mechanical construction which is shown in Fig. 6. This recorderalso makes a record of the settings of the service phase shifters aseffected by the monitoring system |09 and the motor control system 200.

The recording system utilizes apparatus and circuit connections ingeneral similar to those of the monitoring system. Similar referencenumerals, with the prex 50D instead of 100, have therefore been used.This system comprises a Y double commutator bank 5m of the sameconstruction as that of the commutator bank I9.

Condensers 53|, 532, 533, etc. are connected to the respective segmentsof this commutator bank. There is also provided a diode rectier tube 535having a similar circuit to that of the rectier tube 535 and connectedthrough a transformer 535 in parallel with the transformer |34 to theoutput of the amplifier 56. The output of the rectifier 565 suppliescharging current to the condensers 53|, etc. through brush 5| Brush 5| 2is connected to the grid of a vacuum tube 54D which is operated as avoltage responsive device. 5

Under normal conditions, the vacuum tube 540 draws space current fromthe battery 543, holding the relay 552 operated and its contact open.W'hen the charge on any one of the condensers 53|, etc. reaches apredetermined negative value the space current of the tube 559 will bedecreased and the relay 552 will release. This Will complete a circuitfrom battery 586 through the armature of relay 542 and Winding of thedotter solenoid 65| of the recorder 650 and simultaneously through thewinding of relay 58|. The operation of relay 58S completes a circuit toground for the brush 5|2 causing the discharge of that particular one ofthe condensers 53|, etc. the charge on which had reached thepredetermined value. fers from the monitoring system in which all of thecondensers |3|, etc. are discharged on the operation of the vacuum tubecircuit. In the case of the recording system it is desired to obtain arecord of every position at which the eld intensity has reached aparticular value so that only that particular one of the condensers 53|,etc. Which caused the operation of the circuit is discharged.

In order to obtain a record of the operation of the monitoring and motorcontrol systems, there is provided a relay 515, the Winding of which isconnected in parallel with the Winding of the relay |39 and operatessimultaneously therewith on the discharge current oi the condenser |41.The operation of the relay 515 connects the battery 516 to the windingof a second dotter solenoid 692 of the recorder 656.

Referring to Fig. 6 the recorder mechanism 690 comprises a drive for apaper record tape 693 through a drive shaft 694. Traveling transverselyor the tape are two similar continuous belts 655 and 666. These beltsand the associated recording mechanisms are identical, one beingassociated with the dotter solenoid 66| for giving a record of the fieldintensity and the other for dotter solenoid 552 for giving a record ofthe operation of the service phase Shifters. Only one Will ltherefore bedescribed in detail.

In this respect the recording system dif- The belt 605 has mounted onthe inner surface thereof a plurality of levenly spaced styluses 601.Both belts 605 and 606 are driven by a sprocket wheel 608 carried by ashaft 609 geared to or driven synchronously with the shaft 30 thus as astylus 601 passes over the paper tape 603 its position along thetransverse axis of the paper will correspond to an angular position ofthe shaft and consequently of the adjustment of the phase Shiftersmounted on that shaft. Pivoted above the belt 605 is a striker plate 6|0(Support not shown) which is held out of contact with the belt by meansof a spring 6i l. Between the paper 603 and the belt 605 is a typewriterribbon 6 i 2 the drive for which is not shown. Mounted beneath the paper603 and supporting it is a back plate or platen 6M. The dotter solenoid60| is mounted above the Striker plate 610 and has a plunger 613 normalto the striker plate. When the solenoid 60! is energized by theoperation of the recorder circuit 500 as previously described, theplunger 613 will be operated to depress the striker plate 610 bringingthe paper 603, typewriter ribbon 6&3 and a stylus 601 in contact andmaking a dot on the paper 603.

AS previously indicated the arrangement of the mechanism for the dottersolenoid 602 and its associated belt 506 is the Same as for solenoid 6land belt 605. As shown in the drawings, the typewriter ribbon SI2overlaps both of the belts 605 and 606 so that if a two color ribbon isused, the dotters 60! and 62 will make dots of different colors.

The density of the dots made by the dotter solenoid B0! on anyparticular longitudinal line of the paper 603 will give an indication ofthe field strength for that particular angular position of themonitoring phase Shifters and consequently for the corresponding angleof response of the antennae system. The position of the dots made by thedotter solenoid 602 will indicate the particular angular position of themonitoring phase Shifters which cause the operation of the motor controlcircuit to Set the service phase Shifters.

As shown and so far described, the recorder 600 will make a record ofthe operation of only one monitoring control 00 and its associated motorcontrol 200. The operation of one or more other monitoring circuits andassociated motor control circuits such as 300 and M0 may be recorded onthe same record by connecting to the dotter solenoid 602 in parallelwith the contacts of relay 515 the contacts of a similar relay which isconnected in the same way to such second control circuit.

While the automatic phase control system as shown and described aboveoperates with the monitoring phase shifter and the service phase shifterconnected to the same antennae array, it is to be understood that theymay be connected to separate arrays. For example, the monitoring circuitmay be associated with the monitoring phase shifter of the receivingsystem and operate to control the phase Shifters associated with theantennae array of a transmitting system.

Fig. l shows the mechanical arrangement of the phase shifter operatingshift where the receiver is located at one end of the antenna array.When, as would be the more usual case, the receiver is mounted at anintermediate point along an end-on array a different mechanicalarrangement will be required. This is primarily because of the fact thewaves arriving at the antenna units on one side of the receiver arriveat the units more distant from the receiver before arriving at thosecloser thereto while for the antenna units on the other side the waveswill arrive at those closer to the receiver before arriving at thosemore distant.

As described in detail in Patent 2,041,600 the arrangement of themechanism for the simultaneous operation of the phase Shifters dependsupon the spacing of the antenna units and the length of the transmissionlines connecting the antenna units to the phase Shifters. When thereceiver including the phase Shifters is located at an intermediatepoint along the array the group of phase Shifters associated with theunits on one side of the receiver must be adjusted in one direction orsense and the group associated with the antenna units on the other sideof the receiver in the opposite direction. Also, the relative adjustmentbetween the two groups of phase Shifters depends upon frequency of thewaves being received.

Fig. '7 shows a mechanical arrangement for adjusting the phase Shiftersin Such a system. In this figure the phase Shifters 1I and 102 are thephase Shifters for the antenna units on one side of the receiver. PhaseShifters 100 and 105 are those for the antenna units on the other sideof the receiver. The group of phase Shifters and 102 are connectedthrough gears of the proper ratios to a drive shaft 101. The group ofphase Shifters 100 and 105 are similarly geared to a shaft 108. Thelatter shaft 108 is driven by a motor 109 and by means of a differentialgear mechanism 1li) drives the shaft 101 in the opposite direction tocause an adjustment of the phase Shifters 10| and 102 opposite to thatof the phase Shifters 104 and 105 as is required. The pinion 1I Imounted on a shaft with a control knob, not shown, permits theadjustment of the spider 1I2 of the differential gear mechanism to causethe adjustment of the relative phase of the two groups of phase Shiftersas is required, according to the frequency of operation.

What is claimed is:

1. In a steerable antenna system, an antenna array, a plurality of setsof variable phase shifters connected in parallel to certain of theantenna units of said array, a translating circuit connected to theoutput of each Set of phase Shifters, means for continuously, cyclicallycontro-lling one set of phase Shifters to vary the directive response ofsaid system, and means responsive to the Signals in the translatingcircuit connected to Said one Set of phase Shifters for automaticallyadjusting another of Said sets of phase Shifters.

2. In a steerable antenna System, an antenna array, a plurality of setsof variable phase Shifters connected in parallel to certain of theantenna units of said array, a translating circuit connected to theoutput of each Set of phase Shifters, means for continuously cyclicallycontrolling one set of phase Shifters, a plurality of capacitors eachcorresponding to a different point in the cycle of adjustment of saidone Set of phase Shifters, means for charging Said capacitors inproportion to the respective Signal output of the translating circuitconnected to said one set of phase Shifters as Said one set of phaseShifters is cyclically controlled, and means responsive to a chargeabove a predetermined value on any one of said capacitors for soadjusting another of Said sets of phase Shifters that the correspondingtranslating circuit will have a maximum response for waves from acorresponding direction.

3. In a steerable antenna system, an antenna array, a plurality of setsof variable phase Shifters connected in parallel to certain of theantenna units of said array, a translating circuit connected to theoutputs of each set of phase Shifters, means for continuously cyclicallycontrolling one set of phase Shifters to obtain a cyclic variation ofthe effective direction of maximum response, a plurality of capacitorseach corresponding to a different direction of response, means forcharging said capacitors in proportion to the respective signal outputof the translating circuit connected to said one set of phase Shiftersas said one set of phase Shifters is cyclically controlled, and meansresponsive to a charge above a predetermined value on one of saidcapacitors for automatically so adjusting another of said sets of phaseShifters that the corresponding translating circuit Will have a maximumresponse at the direction to which said one capacitor corresponds.

,4. In a steerable antenna system, an antenna array, a plurality of setsof Variable phase shifters connected in parallel to certain of theantenna units of said array, a translating circuit connected to theoutputs of each set of phase Shifters, means for continuously cyclicallycontrolling one set of phase Shifters to obtain a cyclic variation ofthe effective direction of maximum response, a plurality of capacitorseach corresponding to a different direction of response, means forcharging said capacitors in proportion to the respective Signal outputof the translating circuit connected to said one set of phase Shiftersas said one set o-f phase Shifters is cyclically oontrolled, and meansresponsive to a charge above a predetermined value on one of saidcapacitors for automatically soadjusting another of said sets of phaseShifters that the corresponding translating circuit Will have a maximumresponse at the direction to which, said one capacitor corresponds, andmeans also responsive to such charge for causing the discharge of all ofsaid capacitors.

5. A steerable antenna system comprising at least two directive antennaunits, a plurality of Variable phase sl'fters connected to one of saidantenna units, a translating device connected t0- each of Said phaseShifters and to the other antenna, means for continuously cyclicallyvarying one of Said phase Shifters to cyclically change the direction ofresponse at Which the Waves from said antenna and from said one phaseshifter combine in phase in the corresponding translating device, meansfor obtaining a measure of the amplitude of the Waves in saidcorresponding translating device for a plurality of directions ofresponse, and means responsive to Such measure for automaticallyadjusting another of said phase Shifters so that the Waves in thetranslating device connected thereto combine in phase with the Wavesfrom Said other antenna for a direction at which the reception asindicated by the measuring means is above a predetermined value.

6. In combination, a steerable antenna array comprising a plurality ofantenna units, a plurality of sets of Variable phase Shifters, one phaseshifter of each set being connected in the leads from each of certain ofsaid antenna units, and means for simultaneously controlling the phaseshifter of each set so that the outputs thereof are in phase for eachcorresponding angle, means for continuously controlling one of said setsof phase Shifters so that the antenna pattern continuously sweeps thefield of oscillation, means responsive to the output of said one set ofphase Shifters for producing a series of electrical charges proportionalto the eld intensity at the respective angles of reception, and meansresponsive to any one of said electrical charges above a predeterminedvalue for so Setting one of the other of said sets of phase Shiftersthat the maximum reception of said System corresponds to the respectiveangle.V

'7. A combination, according to claim 6, in which the means forproducing electrical charges comprises a rectiner connected to theoutput of Said one set of phase Shifters, a commutator, a capacitorconnected to each segment of said commutator, brush means driven insynchronism with the means for continuously controlling said one set ofphase Shifters and contacting said commutator, means responsive tovoltages above a predetermined value, and connections from said brushmeans to said rectifier and to the voltage responsive means.

8. A combination, according to claim 6, in which the means for producingelectrical charges comprises a rectifier connected to the output of saidone set of phase Shifters, a commutator, a capacitor connected to eachsegment of said commutator, a brush driven in synchronism with the meansfor continuously controlling said one set of phase Shifters, meansresponsive to voltages above a predetermined value, connections fromsaid brush to said rectifier, a second brush driven synchronously Withthe rst brush, connections from said second brush to the voltageresponsive means and means responsive to the operation of the voltageresponsive means for causing said rst brush to successivelyShort-circuit said capacitors for a period of at least one revolution ofthe brush.

9. In a radio receiving system employing an end-on array of directiveantenna units, a plurality of sets of variable phase Shifters, one phaseshifter of each set being connected to each 0f certain of said antennaunits, each of said sets being so mechanically interconnected as to besimultaneously variable to steer the corresponding array directivecharacteristic, a monitoring receiver connected to one set of phasechangers, a service receiver connected to another set of phase changers,means for continuously driving the monitoring set of phase Shifters toobtain a cyclic variation of the phase shift to produce a continuoussweep by the array directive characteristic, a brush-commutatorcombination driven synchronously with Said monitoring set of phaseShifters, said brush-commutator combination comprising two synchronouslydriven brushes and parallel connected commutator segments, one set ofSegments contacting with each of said brushes, a plurality ofcapacitors, one connected to each commutator segment, a rectifierconnected to the output of said monitoring receiver, a connection fromthe output of said rectifier to one ofv said brushes to apply to saidcapacitors in succession negative charges proportional to the amplitudeof the output of the monitoring receiver at the particular instant, avacuum tube voltmeter, a connection from the other of said brushes tothe input of said vacuum tube voltmeter, a relay circuit connected tothe output of said vacuum tube voltmeter, said vacuum tube voltmeterbeing adjusted to operate When the charge on any one of said capacitorsreaches a predetermined value, means responsive to the operation of saidrelay circuit for completing a circuit to said one brush for a timeSufficient to cause the discharge of all of said capacitors, and

means also controlled by said relay circuit for so setting that set ofphase Shifters connected to the service receiver that the correspondingarray directive characteristic is at the saine angle as the arraydirective characteristic of the monitoring circuit at the instant thecharge on the capacitor reaches said predetermined value.

10. In a radio system employing an antenna array of directive antennaunits each connected through a variable phase shifter to a translatingcircuit, means for continuously cyclically varying said phase shiftersto vary the directive characteristic of said system, means for producingfrom the output of said translating circuit a plurality of voltages eachcorresponding to the response of said system at a different particulardirection, and means responsive to said voltages for automaticallycontrolling the direction of radiant action of said system.

11. In a radio system employing an antenna array of directive antennaunits each connected through a variable phase shifter to a translatingcircuit, means for continuously cyclically varying said phase Shiftersto vary the directive characteristic of said system, a plurality ofcondensers each corresponding to a different direction of response,means responsive to the output of said translating circuit for chargingsaid condensers in accordance with the intensity of response at thecorresponding direction, and means responsive to the charge on saidcondensers for automatically controlling the direction of radiant actionof said system.

NORMAN J. PIERCE. FRANK A. POLKlNGI-IORN.

